Cubed tung oil acid



Patented Aug. 20, 1935 CURED TUNG OIL ACID Henry Lyne Plummer, Philadelphiayand Leslie Field Stone, Morton, Pa., assignors to E. I. du

' Pont de Nemours & Company, Wilmington,

Del., a corporation of Delaware No Drawing. Application February 18, 1932,

' Serial No. 593,929

6 Claims. (Cl. 2608) This invention relates to coatingcompositions also pe mi s heating the material to a r latively containing tung oil and more particularly to high temperature for a considerable period of synthetic resinous compositions into which tung m without increasing the s s y undulyoil or its constituents has been incorporated. This method! is p 130 the Objectifln, w

Coating compositions containing tung oil as a that the presence of the rosin injures the color 5 drying oil constituent are, as is well known, suband the durability of the film. If large amounts ject to the disadvantage of producing films which are used, it also prevents the drying of the film readily frost. Prior attempts to produce a cured to a satisfactory condition. The addition of the tung oil have been concerned chiefly with heating other oils referred to above in the quantity nec- 10 the oil itself and diluting it with various mateessary to p ev t frosting f e Oil p rials. These methods have been more or less tions is objectionable b a e f Slower dr in ineffective because they do not attain the object and poor water resistance of the films obtained. sought for, or because of the polymerization and This invention has as an object a process for undesirable increase in viscosity which takes place treating tung oil acids and formulating them into 5 when tung oil is heated to a high temperature. synthetic'oils and coating compositions, the films The same disadvantages have also been experiof which are not subject to frosting. Another enced in coating compositions made with synobject is the production of a cured synthetic tung thetic resins of the polyhydric alcoholepolybasic oil. A still further object is the preparation of acid type which contain tung oil in combined synthetic resins, and particularly polyhydric alform as a constituent. Small amounts of this oil cohol-polybasic acid resinous coating composi- 20 may be incorporated directly into this type of tions, containing tung oil or its equivalent in resin by simply allowing the other ingredients considerable quantities, which shall dry satisof the resinous composition to react in its presfactorily without the frosted appearance which once. Another common and more satisfactory very frequently occurs in coating compositions way is to replace part of the polybasic acid used containing considerable quantities of this oil. 5 in the resinous coating composition by the mix- We have discovered that while tung oil acids ture of acids-obtained from the saponification esterified with polyhydric alcohol (as for instance of tung'xoil." According to this method the glycertung oil itself which is the triglyceride of tung ide of tung oil acids is synthesized during the oil acids) cannot be heated to a high temperaprocess of resinification and thoroughly combined ture without polymerization, the isolated tung 30 with the resinous substance. Any desired amount oil acids can be heated to a high temperature of tung oil may be used in this way. without appreciable polymerization and when so The use of large amounts of tung oil in these heated the acids are cured in that they may resinous compositions is, however, attended by be formulated into' coating compositions which certain disadvantages. The dried film, instead of do not exhibit the frosting tendency of compo- 5 being clear, frequently presents a frosted appearsitions made from tung oil. This fact makes itance similar to that which is obtained with cerpossible, when the cured acids are esterified (as tain oleoresinous varnishes containing large for instance with glycerine for the production of amounts of tung oil. Various methods have been synthetic tung oil or synthetic resin), to so alter 4o tried in order to overcome this defect, as for the unsaturated portion of the tung oil glyceride 40 instance theuse of active driers which control by heat treatment that frosting will not occur to some extent the tendency of the film to frost. in the film at any timeduring the drying period Heating of the ingredients to a high temperature or thereafter, provided drier is added as is cusis sometimes resorted to. This, however, results tomary in tung 011 om o iti inasmuch as in a resin of very high viscosity which requires any tung oil or a varnish or synthetic resin na- 45 a large amount of solvent to bring its solution ture, no matter how processed, will frost under to a viscosity satisfactory for application, and the some set of drying conditions unless suitable film laid down with this solution is too thin to driers are added, we desire it to be understood be satisfactory. The solutions also are unstable. that by the term non frosting films" in the 60 Another method which has been used consists claims we mean films obtained from our comof the use of considerable quantities of rosin or positions when they contain a reasonable amount other natural gums or other drying or semiof drier to accelerate the drying of the film, as drying oils in conjunction with the synthetic for instance cobalt drier (containing .03% of resin. The presence of the resin does in itself metal based on oil content) or its drying equivadecrease this tendency to frost to some extent and lent in other metals.

period of time varying inversely from twenty to sixty five minutes. Tung oil acids, as well understood by those skilled in the art, are conveniently obtained from tung oil, which is also known as China-wood oil, by any of the common methods usually used in obtaining an acid from an ester such as hydrolysis or saponification.

The method of carrying out our invention is best illustrated by the following examples, I and II, showing the method of producing the cured tung oil acids, the remaining examples showing the methods of utilizing the cured acids.

Example I Heat tung oil acids to 575 F., hold at this temperature for about 30 minutes and cool and use.

. Example II Heat tung oil acids to 550 F., hold at this temperature for about 50 minutes and cool and use.

Synthetic cured tung oil may be madefrom the curedacids as follows:

Example III Heat 310 parts of cured tung oil acids and 92 parts of 100% glycerol or its equivalent of another polyhydric alcohol to about 400 F. Heat at 400 F.'until an acid number of about 10 is obtained. The exact proportion of the ingredients will vary somewhat depending on the acid number of the tung oil acids used in the esterification.

The following threeexamples show the method of incorporating the cured tung oil acids into synthetic resins of the polyhydric alcohol-polybasic acid type:

Example IV Heat 647.5 parts alkali refined linseed oil and 146 parts C. P. glycerol to 437 F: and add 0.7 parts litharge. Hold at 437 F. until a sample of mixture when cooled is clear and homogeneous (about 20 to 30 minutes). Add 747.6 parts phthalic anhydride and 248.7 parts of the cured-tung o'il acids of Example I and heat back to 437 F. Add 206 parts C. P. glycerol and-heat to 437 F. Hold at this temperature to an acid number of about 35 to 40. A 45% solution in toluol should give a Gardner-Holdt viscosity of about C. Reduce in the appropriate coal tar solvent to desired voltaile content and physical constants. After addition of 15 parts of either cobalt or manganese linoleate solution (containing 2% and 3% metal, respectively) the composition is ready for application.

Example V Add 2392.2 parts phthalic acids of Example I and heat to 392 F. Add 930.5 parts C. P. glycerol and heat to 392 F. Hold at 392 F. to an acid number of 45 to 55. A 50% solution in xylol should give a Gardner-Holdt viscosity of about X. Reduce in the appropriate coal tar solvent to desired volatile content and physical constants. Add 40 parts of either cobalt or manganese linoleate solution (containing 2% and 3% metal, respectively). This resulting varnish is ready for application.

Example VI Heat 1128.4 parts alkali refined linseed oil and 225.8 parts C. P. glycerol to 437 F. Add 11.3 parts litharge. Hold at 437 F. until a sample of the mixture cooled is clear and'homogeneous (about 20 to 30 minutes). Add 1186.4 parts phthalic anhydride and 1083.6 parts of the cured tung oil acids of Example II and heat back to 392 F. Add 395.9 parts C. P. glycerol and heat to 437 F. Hold at 437 F. to an acid number of 35 to 45. A 40% solution in a coal tar naphtha (boiling range 150 to 200 C.) should give a Gardner-Holdt viscosity of about E. Reduce in the appropriate coal tar solvent to desired volatile content and physical constants. Add 35 parts of either cobalt or manganese linoleate solution (containing 2% and 3% metal, respectively). The resulting varnish is ready for application.

Although the above examples are limited to" the use of linseed oil in connection with tung oil, it is to be understood that other oils, such as perilla, sunflower or fish oil, may be used if desired. These oils may be incorporated directly as such or they may be incorporated by using the products of their hydrolysis as in the manner well known to those skilled in the art. These resins may also be made with the tung oil acids without the addition of other oil or oil acids, although low acid values cannot be obtained without un duly high viscosities.

The polyhydric alcohols and polybasic acids usually used in the manufacture of polyhydric alcohol-polybasic acid resins may be used in making the improved resins described herein. Other suitable polyhydric alcohols are: ethylene glycol, sorbitol, and pentaerythritol. These and other polyhydric alcohols may also be used instead of glycerol for making the synthetic cured tung oil of Example III. As-suitable polybasic acids other than phthalic there may be mentioned succinic and maleic as well as any of the polybasic acids known by those skilled in the art to be useful in the manufacture of polyhydric alcohol-polybasic acid resins. The usual modifyingagents such as rosin or other natural gums or resin acids may be included in the reaction mixture of the resin ingredients. The use of these gums is, however, in no way necessary to the practice of this invention.

Other synthetic resins into which fatty oils or oil acids are advantageously incorporated may also be improved by the use of the cured tung oil or oilacids disclosed herein. In making phenol formaldehyde resins for instance, formaldehyde and. cresol may be reacted in the presence of the cured tung oil.

This invention makes possible the preparation of improved coating compositions and resins, and particularly polyhydric alcohol-polybasic acid resins, containing substantial proportions oftung oil or its equivalent and having low vicosity characteristics which will dry to a film having satisfactory physical propcrtics and which will not show a frosted appearance. These qualities are secured without the use of rosin or other holding agent. It is also unnecessary in the practice of our invention to. use excessive amounts of drier.

Our invention is particularly applicable for the preparation of any resinous composition containing the constituents of tung oil in which the acids of tung oil and glycerine or other polyhydric alcohol are employed.

As many apparently widely difierent embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereof except as defined in the following claims:

We claim:

1. A process which comprises heating tung oil acids to a temperature of about 540 F. to 585 F. and thereby obtaining cured tung oil acids.

2. A process of curing tung oil acids which comprises heating tung oil acids at 585 F. to 540 F. for 20 to 65 minutes.

3'. A method of making cured synthetic tung oil which comprises curing tung oil acids by heating them to a temperature of about 540 F. to 585F. and heating the cured acids with a poly-- .hydric alcohol.

of about 540 F. to 585 F. and heating the cured acids with'an organic polybasic acid and polyhydric alcohol until resinification takes place.

6. A method of making polyhydric alcoholpolybasic acid resins which comprisesheating a fatty oil with glycerol and heating the resulting productwith cured tung oil acids, phthalic anhydride and glycerol until resinification takes place, said cured tung oil acids being obtainable by heating tung oil acids to a temperatureof about 540 F. to 585 F.

HENRY LYNE PLUMMER. LESLIE- FIELD STONE. 

